Developing Genkit Go

GoogleOfficialPublished by Google

Skill
Tool integration
Software development
Apache-2.0
Medium risk

From the author

Develop AI-powered applications using Genkit in Go. Use when the user asks to build AI features, agents, flows, or tools in Go using Genkit, or when working with Genkit Go code involving generation, prompts, streaming, tool calling, or model providers.

— the description by Google

AutoGineer summary

Written by AutoGineer from the skill’s own files, not by the author

Genkit Go is an AI SDK that provides a unified interface for integrating generative AI into Go applications. It supports features such as model generation, structured output, streaming, tool calling, and complex agent workflows. The framework is designed for observability and testing, offering a CLI for tracing and a developer UI for inspecting model interactions. It includes experimental support for multi-turn agents, persistent sessions, and generative UI (A2UI) surfaces.

What it does

Provides a unified interface for interacting with various AI model providers.
Enables the creation of flows for structured, observable AI logic.
Supports experimental multi-turn agent development with session persistence.
Offers middleware for common tasks like retries, fallbacks, and artifact management.
Includes a CLI tool for capturing traces, debugging, and running flows.
Facilitates generative UI integration via A2UI middleware.

When to use it

When building AI features, chatbots, or agents within a Go codebase.
When you need to integrate multiple AI model providers with a consistent API.
When you require observability, tracing, and structured testing for AI logic.
When developing conversational interfaces that require state management or human-in-the-loop capabilities.

Advantages

Unified API across different model providers.
Strong observability through integrated tracing and CLI tools.
Separation of concerns between AI logic and application code via flows.
Extensible middleware system for common AI patterns.
Experimental support for advanced agent features like branching and artifacts.

Usage examples

“How do I define a simple flow in Genkit Go?”: You use genkit.DefineFlow to wrap your AI logic, which automatically enables tracing and HTTP deployment capabilities.
“How can I debug my AI model calls in the terminal?”: Use the Genkit CLI by running 'genkit start -- go run .' to capture traces and inspect model I/O in the Developer UI.

Install

Download the skill as a ZIP:
https://autogineer.com/agent-skills/google/developing-genkit-go/download

Unzip it into the cross-client skills folder of your project:

mkdir -p .agents/skills && unzip developing-genkit-go.zip -d .agents/skills

Documentation by Google

Genkit Go

Genkit Go is an AI SDK for Go that provides generation, structured output, streaming, tool calling, prompts, and flows with a unified interface across model providers.

Hello World

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"

	"github.com/firebase/genkit/go/ai"
	"github.com/firebase/genkit/go/genkit"
	"github.com/firebase/genkit/go/plugins/googlegenai"
	"github.com/firebase/genkit/go/plugins/server"
)

func main() {
	ctx := context.Background()
	g := genkit.Init(ctx, genkit.WithPlugins(&googlegenai.GoogleAI{}))

	genkit.DefineFlow(g, "jokeFlow", func(ctx context.Context, topic string) (string, error) {
		return genkit.GenerateText(ctx, g,
			ai.WithModelName("googleai/gemini-flash-latest"),
			ai.WithPrompt("Tell me a joke about %s", topic),
		)
	})

	mux := http.NewServeMux()
	for _, f := range genkit.ListFlows(g) {
		mux.HandleFunc("POST /"+f.Name(), genkit.Handler(f))
	}
	log.Fatal(server.Start(ctx, "127.0.0.1:8080", mux))
}

Core Features

Load the appropriate reference based on what you need:

Feature	Reference	When to load
Initialization	references/getting-started.md	Setting up `genkit.Init`, plugins, the `*Genkit` instance pattern
Generation	references/generation.md	`Generate`, `GenerateText`, `GenerateData`, streaming, output formats, `Embed`
Prompts	references/prompts.md	`DefinePrompt`, `DefineDataPrompt`, `.prompt` files, schemas
Tools	references/tools.md	`DefineTool`, `DefineResumableTool` interrupts (`Interrupted` claim, `Restart`/`Respond`, `WithResume`), `ai/tool` helpers (`tool.Interrupt`, `tool.Fail`, `tool.AttachParts`)
Middleware	references/middleware.md	`ai.Middleware`, `ai.WithUse`, `Hooks` (Generate/Model/Tool), built-ins (`Retry`, `Fallback`, `ToolApproval`, `Filesystem`, `Skills`, `SoftToolErrors`, `ContextCompression`, `Budget`)
Observability	references/observability.md	OpenTelemetry export (`otelgenai`), `tracing.SetInstrumentation`, `aix.Observer`, reflection API outside dev
Flows & HTTP	references/flows-and-http.md	`DefineFlow`, `DefineStreamingFlow`, `genkit.Handler`, HTTP serving
Model Providers	references/providers.md	Google AI, Vertex AI, Anthropic, OpenAI-compatible, Ollama setup

Agents (Experimental)

Genkit Go has an experimental agent API for persistent, multi-turn conversations (sessions, snapshots, interrupts, branching, background execution). It is gated: initialize with genkit.Init(ctx, genkit.WithExperimental()) or the constructors panic. Server constructors come from genkit/exp (aliased genkitx); types and options from ai/exp (aliased aix); session stores from ai/exp/localstore.

Agent or flow? If the task is conversational, multi-turn, or described as "an agent", "assistant", or "chatbot", build it with genkitx.DefineAgent rather than hand-rolling a Generate + tools loop in a flow. Reach for a plain flow only for single-shot, stateless generation.

For details see:

Agents: defining/serving an agent, running turns, and client- vs server-managed state (start here).
Sessions & persistence: session stores (localstore.NewInMemorySessionStore/NewFileSessionStore, PostgreSQL), snapshots, and the sessionstoretest conformance suite.
Human-in-the-loop / interrupts: pausing for approval/input and resuming.
Branching: forking a conversation from a snapshot.
Background agents: detaching long-running turns and polling.
Working with state: typed custom session state, streamed as JSON patches.
Artifacts: producing and reading named deliverables.
Multi-agent orchestration: delegating to sub-agents, background delegation, continue_task, and remote agents (DefineRemoteAgent).
Advanced custom agents: DefineCustomAgent for full turn control.
Deploying agents: serving agents over HTTP with genkit.Handler.

Generative UI (A2UI)

Genkit Go has an A2UI (Agent-to-UI) plugin (github.com/firebase/genkit/go/plugins/a2ui/exp, imported as a2uix) that lets an agent stream interactive UI surfaces (cards, lists, forms, buttons), not just prose. The whole integration is the &a2uix.Surfaces{} model middleware added via ai.WithUse on a generate call or agent inline prompt. Go is server-only: it has no A2UI client/renderer. Render surfaces with a JS or Dart/Flutter client that talks to your Go agent over HTTP (the server and clients are wire-compatible).

A2UI: server middleware, options, custom catalogs, and security. For the client (rendering surfaces), refer to the A2UI reference in the Genkit JS or Dart skill.

Genkit CLI (recommended)

genkit start unintrusively wraps any Go program that uses the Genkit library, running it unchanged while capturing traces from every Genkit action so you can prove tools were actually called and inspect model I/O from the terminal, even for headless checks. It forwards stdio, so interactive CLI tools that rely on stdin/stdout work without issues. Running the app directly (go run .) skips trace capture, so you're debugging blind. Check install with genkit --version.

Installation:

curl -sL cli.genkit.dev | bash

Primary pattern (default): prefix genkit start -- to your normal run command. This collects telemetry from any Genkit code your program runs, whether triggered from the dev UI, your own web server/web UI, or a plain script. Starts the Developer UI (usually http://localhost:4000) for running flows, model and agent playground, and browsing traces:

genkit start -- go run .
genkit start --noui -- go run .   # same, without the Dev UI (still a persistent server)
genkit start -o -- go run .       # also opens the browser

genkit start runs until you stop it with Ctrl+C. That is expected and correct for the common cases: a server your web/mobile app calls, or an interactive CLI you exit yourself. --noui only drops the Dev UI; it is not a one-shot command and will not exit on its own. Do not use genkit start as a blocking step in automated/non-interactive contexts; use flow:run (below) for that.

Non-interactive use (agents/CI): add the global --non-interactive flag before -- so the CLI uses defaults and never blocks on a prompt (e.g. the first-run analytics notice): genkit start --non-interactive -- go run . (works with flow:run too).

Run a flow (flow:run): invoke a specific flow by name from the CLI. Append your run command after -- to spin up the runtime just for this run (the command runs as-is to register your flows):

genkit flow:run myFlow '{"data": "input"}' -- go run .
genkit flow:run myFlow '{"data": "input"}' --stream -- go run .   # with streaming
genkit flow:run myFlow '{"data": "input"}' --wait -- go run .     # wait for completion

This is self-terminating: it runs the flow once, prints a Trace ID, then exits, so it's the right choice for a quick, non-interactive check (unlike genkit start). Traces for this run can be inspected using the trace commands below.

Debugging with traces: the fastest way to see prompts, model inputs/outputs, tool calls, latencies, and errors. Inspect from the terminal after any run under genkit start:

genkit trace:list                        # find recent trace IDs
genkit trace:get <traceId>               # full trace details (inputs, outputs, tool calls, errors)
genkit trace:get <traceId> --format json # machine-readable JSON, safe to pipe into jq or other parsers

For machine-readable output, pass --format json to get clean JSON you can pipe into jq or other parsers. The default output is human-oriented (banner/log lines, possible truncation on large traces), so don't pipe that form directly; use --format json, grep, or the Dev UI trace viewer.

Documentation:

genkit docs:search "streaming" go
genkit docs:list go
genkit docs:read go/flows.md

See references/getting-started.md for full CLI and Developer UI details.

Key Guidance

Pass g explicitly. The *Genkit instance returned by genkit.Init is the central registry. Pass it to all Genkit functions rather than storing it as a global. This is a core pattern throughout the SDK.
Wrap AI logic in flows. Flows give you tracing, observability, HTTP deployment via genkit.Handler, and the ability to test from the Developer UI and CLI. Any generation call worth keeping should live in a flow.
Verify with traces, not a blind run. Running the app directly (go run .) does not capture dev traces. See the Genkit CLI section for how to run your app and capture traces.
Use jsonschema:"description=..." struct tags on output types. The model uses these descriptions to understand what each field should contain. Without them, structured output quality drops significantly.
Write good tool descriptions. The model decides which tools to call based on their description string. Vague descriptions lead to missed or incorrect tool calls.
Use .prompt files for complex prompts. They separate prompt content from Go code, support Handlebars templating, and can be iterated on without recompilation. Code-defined prompts are better for simple, single-line cases.
Use DefineResumableTool for interrupts. Claim paused calls with the tool's Interrupted method and resume with ai.WithResume. ai.InterruptWith, RestartWith/RespondWith, and WithToolRestarts are deprecated; genkitx.DefineInterruptibleTool and ai/exp/tool were removed in v1.14.0. See references/tools.md.
Reach for built-in middleware before writing one. Retry, Fallback, ToolApproval, Filesystem, Skills, and SoftToolErrors cover the common cross-cutting needs and compose with each other via ai.WithUse. See references/middleware.md. When you do write custom middleware, allocate per-call state in closures captured by New, and guard anything that WrapTool mutates because tools may run concurrently.
Look up the latest model IDs. Model names change frequently. Check provider documentation for current model IDs rather than relying on hardcoded names. See references/providers.md.

Files

ATTRIBUTION.mdAdded by AutoGineer858 B
LICENSELicence file added by AutoGineer11.1 KiB
SKILL.md11.0 KiB
references/a2ui.md11.9 KiB
references/agents-artifacts.md3.9 KiB
references/agents-background.md5.3 KiB
references/agents-branching.md3.6 KiB
references/agents-custom.md6.8 KiB
references/agents-deployment.md6.6 KiB
references/agents-human-in-the-loop.md7.3 KiB
references/agents-multi-agent.md9.3 KiB
references/agents-sessions.md8.3 KiB
references/agents-state.md4.6 KiB
references/agents.md13.0 KiB
references/flows-and-http.md4.4 KiB
references/generation.md5.3 KiB
references/getting-started.md3.4 KiB
references/middleware.md19.9 KiB
references/observability.md4.3 KiB
references/prompts.md7.0 KiB
references/providers.md3.6 KiB
references/tools.md8.3 KiB

LICENSE


                                 Apache License
                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.

      "Work" shall mean the work of authorship, whether in Source or
      Object form, made available under the License, as indicated by a
      copyright notice that is included in or attached to the work
      (an example is provided in the Appendix below).

      "Derivative Works" shall mean any work, whether in Source or Object
      form, that is based on (or derived from) the Work and for which the
      editorial revisions, annotations, elaborations, or other modifications
      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions
      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but
      excluding communication that is conspicuously marked or otherwise
      designated in writing by the copyright owner as "Not a Contribution."

      "Contributor" shall mean Licensor and any individual or Legal Entity
      on behalf of whom a Contribution has been received by Licensor and
      subsequently incorporated within the Work.

   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their
      Contribution(s) alone or by combination of their Contribution(s)
      with the Work to which such Contribution(s) was submitted. If You
      institute patent litigation against any entity (including a
      cross-claim or counterclaim in a lawsuit) alleging that the Work
      or a Contribution incorporated within the Work constitutes direct
      or contributory patent infringement, then any patent licenses
      granted to You under this License for that Work shall terminate
      as of the date such litigation is filed.

   4. Redistribution. You may reproduce and distribute copies of the
      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and
          attribution notices from the Source form of the Work,
          excluding those notices that do not pertain to any part of
          the Derivative Works; and

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or
          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and
      may provide additional or different license terms and conditions
      for use, reproduction, or distribution of Your modifications, or
      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of
      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

   7. Disclaimer of Warranty. Unless required by applicable law or
      agreed to in writing, Licensor provides the Work (and each
      Contributor provides its Contributions) on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
      implied, including, without limitation, any warranties or conditions
      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
      PARTICULAR PURPOSE. You are solely responsible for determining the
      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly
      negligent acts) or agreed to in writing, shall any Contributor be
      liable to You for damages, including any direct, indirect, special,
      incidental, or consequential damages of any character arising as a
      result of this License or out of the use or inability to use the
      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all
      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.

   9. Accepting Warranty or Additional Liability. While redistributing
      the Work or Derivative Works thereof, You may choose to offer,
      and charge a fee for, acceptance of support, warranty, indemnity,
      or other liability obligations and/or rights consistent with this
      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

   END OF TERMS AND CONDITIONS

   APPENDIX: How to apply the Apache License to your work.

      To apply the Apache License to your work, attach the following
      boilerplate notice, with the fields enclosed by brackets "[]"
      replaced with your own identifying information. (Don't include
      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

Requirements and compatibility

Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta

“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.

Security

What our scanner noticed· Medium risk

Downloads piped into a shell

A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.

Attribution and licence

Published by

Google

Publisher

Google (Official)

Source

google/skills · skills/cloud/developing-genkit-go · commit 2194d3b

Licence

Apache License 2.0 (redistribution allowed)

LICENSE (added by AutoGineer from LICENSE)
ATTRIBUTION.md (written by AutoGineer)

Synced

2026-11-09

AutoGineer is not affiliated with or endorsed by Google or Google.

Download ZIP

The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download developing-genkit-go.zip